Emodin

Emodin (from Rheum emodi, a Himalayan rhubarb) is a purgative resin, 6-methyl-1,3,8-trihydroxyanthraquinone, from rhubarb, buckthorn and Japanese knotweed (Fallopia japonica syn. Polygonum cuspidatum). It can also be isomers in botanical extracts.